Signaling device



July 6, 1943. E. DICKTEN, JR, ETAL S IGNALING DEVI CE Filed Oct. 22, 1940 2 Sheets-Sheet l R m N b V. E m M A 0 m U a a A S o" a w m M v. w a 2 m G 2 w I 4 F 8 8 7 @w a; WM 7 \IIIIII 2 l| FINN W a l/ y 6 1 HHHHHIIIIHIAIHH 6 S I 2 a umb 5 July 6, 1943. I E. DICKTEN, JR., ET AL 2,323,803

SIGNALING DEVICE Filed Oct. 22, 1940 2 Sheets-Sheet 2 FIGS E. D/CKTE/V, JR.

INVENTORSIHCHA S A T TO/PNE Y Patented July 6, 1943 UNITED STATES PATENT OFFICE SIGNALING DEVICE Emil Dickten, Jr., Totowa, N. J., and Henry C. Harrison, Port Washington, N. Y., assignors to Bell Telephone Laboratories, Incorporated,

7 Claims.

This invention relates to electromagnetically operated signaling devices and particularly to telephone ringers.

It is the object of this invention to provide a simple, compact and highly efiicient ringer of the type employed extensively at telephone subscriber stations for signaling purposes, and to provide a structure which permits the mounting of the substation induction coil together with the ringer structure in a single sound emitting device, or ringer gong.

This object is attained in accordance with a feature of the invention, by utilizing a simplified stator core structure which readily accommodates the ringer coils and the induction coil with a minimum of iron, thus materially reducing the space occupied by the structure and rendering it suitable for mounting in a housing comprising a single sound emitting element, or gong. The stator structure is such also that the ringer coils and the induction coil are positioned conjugate to each other so that currents in either one will not induce voltages in the other.

Another feature of the invention resides in a structure which permits the rotor, pole-shoes,

rotor shaft extensions and clapper support to be assembled as a unitary assembly and thus to be readily positioned as a unit in the bearings in which the assembly functions. This feature reduces the number of parts required and materially simplifies the assembly of the ringer.

A further feature of the invention resides in the use of a single mounting screw which serves to support the combined ringer and induction coil on the gong housing.

Still another feature of the invention contemplates the use of a squared gong having secured thereto, at a point opposite the ringer clapper, a small stiff reed, and in rendering the gong, with its reed, adjustable with respect to the point of contact between the clapper and reed, whereby; tile sound intensity of the ringer may be regu- These and other features of the invention will be readily apparent from the following detailed description made with reference to the accompanying drawings, in which:

7 Fig. 1 is a plan view of the combined ringer and induction coil looking into the cup-shaped housing which supports the device;

2 is a side View of the structure shown in Fig. '1 and constitutes a section taken along the line 22 of Fig. 1, looking in the direction of the arrows;

Fig. 3 is a top View of the structure disclosed in Fig. 1 with a portion of the gong broken away;

Fig. 4 is a schematic representation illustrating the form of the stator core showing the position of the ringer coils thereon;

Fig. 5 is a view of the induction coil and its removably mountable core;

Fig. 6 is a side view of the core structure which supports the induction coil;

Fig. 7 is a view illustrating the unitary rotor assembly;

Fig. 8 is another view of the rotor assembly; and

Figs. 9 and 10 illustrate fragmentary details of the rotor assembly.

Referring to the drawings, and particularly to Fig. 4, the stator element of the ringer is a laminated structure comprising a plurality of silicon steel laminae, each having the general configuration illustrated. The stator core structure consists of four legs Ill, H, I 2 and i3 which define a rectangle. Extending vertically (viewing Fig. l) from the horizontal leg I 0 is a pair of spaced core extensions l4 and 15, located in the plane of the rectangular section. The extensions l4 and [5 are spaced in from the edges of the rectangular core portion with the outer edge of extension I 5 in substantial alignment with the inner edge of leg II, and the outer edge of extension M in substantial alignment with the inner edge of leg 13. Each of the extensions l4 and i5 carries a ringer coil 15 and H, respectively. The coils IG and I! may be form-wound between the spoolheads [8 and I9 and slipped over the ends of the stator extension l4 and I5. Preferably, each layer of winding of the coils l6 and l! is separated by a thin layer of cellulose acetate and the entire coil encased in a vincellatate covering. The upper face portions of the horizontal leg I!) of the stator constitute shoulders upon which the coils I6 and I! rest.

Each lamina of the stator is provided with a plurality of holes 2!] which, when the laminae are assembled, are in alignment and accommodate the screws 2|. The three lower screws 2| are screwed into tapped holes in a clamp plate 23 which, as illustrated in Fig. 4, extends across the rear face of the lower leg I 2 of the stator core and part way up the vertical legs II and I3. The three upper screws 2| pass through the aligned holes 20 in the upper leg ll] of the stator and are screwed into correspondingly tapped holes in the rectangular mounting block 24 which covers the rear face of the core leg Ill. Thus it will be observed that the mounting block 24 and clamp plate 23 serve to maintain the laminations of the rectangular portion of the stator core in a unitary assembly when the screws 2| are made up tight. The screws'Zl on the vertical legs II and I3 also serve to mount the terminal blocks 26 and 21 on the stator structure.

Near the upper end of the stator extensions M and i5, that is, just above the upper spoolheads Hi, the laminae are cut away at 29 to provide grooves for the reception of two substantially cylindrical sleeves 30 (Fig. 3) which separate the front bearing plate 3| from the rear bearing plate 32 and through which, and through aligned holes in the plates 3| and 32, pass the screwbolts 33. The nuts 34 are made up on the threaded ends of the bolts 33 and thus securely clamp the laminations of the stator extensions [4 and I together. The bearing plates 3! and 32, as will be learned from a later description, serve to mount the rotatable armature between the arcuate pole-faces of the stator extensions l4 and [5.

A metal strap 36 is also mounted on the structure by means of the left-hand (Fig. 3) bolt 33, and is so formed as to have one surface portion abutting the outer face of the bearing plate 3| at 31, and an outer portion spaced therefrom and provided with a hole through which the left-hand bolt 33 extends to receive the nut 34. To the portion of strap 36 which abuts the bearing plate 3|, there is secured a clapper stop 4|] by means of screw 4|.

The bearing plates 3| and 32 are, in effect, bridge pieces, each consisting of a U-shaped portion, each end of which is provided with a flange portion which is bored to receive the screw bolts 3 33. The rear bearing plate 32 is provided with a centrally located hole into which is fitted a cylindrical T-shaped bearing 42, with the head thereof situated on the inside of the bearing plate and provided with a centrally located bore which, as will be seen from a later description, accommodates one of the rotor hubs or ends. This bearing is preferably made of brass.

A similar brass bearing 43 is supported in a centrally located aperture in the bearing plate r 3| and, as will be seen from a later description, houses the other rotor hub or end.

The rotor assembly is shown in Figs. 7 and 8 and as illustrated, comprises a permanent magnet rotor 50, soft iron pole-shoes 5|, clapper arm 52 and the stud shaft assemblies. The permanent magnet 50 is substantially square in crosssection and has its edges beveled. It is made of cast magnet steel and is magnetized so that the north pole is located on top, viewing Figs. 1 and 8, and the south pole at the bottom. The poleshoes 5|, two in number, are open-ended troughlike elements which are secured to the armature 50 by spot welding or by any other suitable process. The pole-shoes are positioned on the permanent magnet with the inner face of their bases abutting opposite faces of the magnet, and with their sides projecting in a slightly arcuate fashion over two opposite sides of the magnet. The

pole-shoe sides are curved to conform with the general contour of the stator pole-faces.

A stud 53, preferably of stainless steel, is fixedly associated with a rectangular sheet 54 of the same material, which sheet is spot welded to the inner edges of the two pole-shoes 5|. The stud 53 is centrally located on the sheet 54, and the sheet 54 is so positioned on the pole-shoe edges that the axis of the stud is in alignment with the center line of the rotor, that is, with its axis of rotation.

The clapper arm 52, clearly illustrated in Fig. 8, consists of an irregularly-shaped sheet of stainless steel having a substantially rectangular por tion thereof spot welded to the front edges of the pole-shoes 5| in a manner similar to that in which the sheet 54 is secured to the rear edges of the pole-shoes. The rectangular portion of clapper arm 52 is provided with a centrally located hole into which is securely fitted a stud 56. When the sheet 54 and the clapper arm 52 have been correctly positioned and welded to opposite edges of the pole-shoes 5!, the axes of studs 56 and 53 will be in alignment with each other and with the axis of rotation of the rotor 50. Each of the studs 56 and 53 terminates in a pin or shaft-like projection having a smooth rounded end. The rounded projection of stud 56 fits into the bearing 43, whereas the projection of stud 53 fits into the bearing 32. These elements fit freely in their respective bearings so that the rotor is free to rotate when the ringer coils l6 and I1 are energized.

As viewed in Fig. 8, the clapper arm 52 is provided with arm-like extensions projecting in either direction from the rectangular portion thereof which is spot welded to the rotor poleshoes 5|, as just described. At the outer edge of the left extension of the clapper arm 52 there is located a small integral, substantially rectangular piece 58, which, when the clapper arm is in position on the ringer structure, assumes a position immediately above the clapper stop 45, as clearly shown in Figs. 1 and 2. When the ringer coils are energized and the rotor functions to actuate the clapper arm 52, the projection 58 thereof strikes against the cam-like periphery of the stop to arrest the motion of the clapper arm. The stop 46 may be adjusted so that the stroke of the clapper arm may be regulated to any desired length.

The end of the right-hand extension (still viewing Fig. 8) of clapper arm 52 terminates in a substantially U-shaped integral formation 69, one of the legs thereof terminating in a ringshaped support for the dome-shaped clapper 6|. The clapper 6! is provided with a small shank portion 62 which tightly fits into the opening in the ring-shaped support.

A spiral spring 63 serves to bias the rotor to a normal position, in which position the axis of the permanent magnet, passing from the north pole to the south pole, is at right angles to the center line of the stator pole-face. This is the position illustrated in Figs. 1, 2 and 3. When the stator windings l6 and ill are energized, the permanent magnet rotor rotates in an eifort to align the field of its magnet with that between the pole-faces of the stator. When this occurs the clapper arm 52, viewing Fig. 1, moves counterclockwise, causing the clapper 52 to strike the gong 55.

Though the adjustable clapper stop 10 may be employed to adjust the stroke of the ringer and thus regulate the sound output of the ringer, an auxiliary means, in the nature of a small stiff reed 55, is also illustrated whichserves to adjust the volume of the ringer. ihis reed is shown riveted to the gong in a position such that the clapper 6!, when actuated, strikes it. The gong 55 is rotatable relative to the structure it houses so that the reed 66 may be moved relative to the clapper 5| and, depending upon its location, will be struck nearer or further away from its point of attachment to the gong. Simple rotation of the gong 65 brings any desired point of the reed under the clapper and permits adjustment of the ringer to give an output appropriate to its surroundings.

Particular reference will now be made to Figs. 4, and 6.

In Fig. 6 there is shown a side view of the laminated core which carries the substation induction coil H. This core structure comprises.

a plurality of similarly formed, rectangular laminae secured together as a unit by means of rivets 12. At one end of the assembly there are two outer laminations which are of greater length than the other laminations of which the core is formed. These two laminations extend above and below the other laminations to provide flange-like extensions which are apertured to receive those screws 2| which coact with the center holes in the horizontal legs l0 and I2 of the stator core. The core 10, with its associated coil H, is slipped into the rectangular area defined by the stator legs I0, H, l2 and [3 so that the apertures or holes in the two outer laminae are in alignment with the center holes 20 in the stator. The corresponding screws 2| are then fed through the aligned holes in stator legs l0 and I2, and in the extensions of the outer laminae of core 10 and their respective nuts screwed thereon. Thus the induction coil of the substation is removably mounted on the stator core and is so positioned that a condition of conjugacy exists between it and the ringer coils l6 and I 1. With this construction the stator of the ringer and the core of the induction coil are combined in a manner to give a saving in the amount of iron used, and in the space it occupies, while the coils of the two units are positioned conjugate to each other so that currents in either one will not induce voltages in the other.

The gong 65 is cup-shaped and its rim contour is preferably squared. The apex of the gong is provided with a slight depression having a centrally located opening for the passage of a screwbolt which is screwed into the tapped aperture, or hole 16 in the mounting block 24, which, as hereinbefore described, is positioned on the rear face of the horizontal leg ID of the stator. A shouldered bushing ll is accommodated in the hole in the gong apex and a rubber washer I8 is interposed between the shoulder portion of the bushing 11 and the inner face of the gong. The inner face of the bushing Tl abuts the rear edges of the spool-head of the induction coil ll. 19 indicates a fragmentary portion of a bell-box cover, base of a combined telephone handset, or any other instrumentality upon which the ringer is to be mounted. When the screw-bolt I5 is screwed into the tapped hole 16, the entire ringer and its associated induction coil are held secured in position on the element 19. To remove the entire structure from the gong housing it is necessary only to remove the single screw-bolt 15 and lift the structure out.

The rotor assembly, as hereinbefore described, comprises the permanent magnet rotor 50, its pole-shoes 5|, the clapper 6i and its supporting arm 52. The clapper is secured to the rotor as hereinbefore described, in such a way that the masses of the rotor and clapper, together with the stillness of the retractile spring form a mechanical system which is resonant at the frequency of the current employed to energize the ringer coils I6 and I1.

The ringer structure as described above has many desirable advantages over ringers of known design. structurally it is compact, it occupies a minimum of space, produces a louder signal, and, because of the use of a single large gong it permits a lower pitched and more pleasant tone.

What is claimed is:

l. A telephone ringer comprising a permanent magnet rotor, a stator having a pair of spaced core legs terminating in oppositely disposed polefaces, a gong, a clapper arm, and means for supporting said rotor between the pole-faces of said stator for rotation therebetween comprising a pair of bearing plates each of which bridges said core legs on opposite sides thereof, a projection of said clapper arm fixed to one side of said rotor and constituting a hub support, a second hub support fixed to the opposite side of said rotor, a hub mounted in a centrally located aperture in each of said hub supports, and a bearing mounted on each of said bearing plates for receiving said hubs, and means carried by said clapper arm and adapted to strike said gong when said rotor is actuated.

2. A telephone ringer comprising a permanent magnet rotor of cast magnet steel, a pair of soft iron pole shoes welded to said rotor, a stator having a pair of spaced core legs terminating in oppositely disposed pole-faces and each carrying a ringer coil, a gong, a clapper arm carrying means for striking said gong when said rotor is rotated between said stator pole-faces upon energization of said ringer coils, and means for rotatably supporting said rotor between said stator pole-faces, comprising a hub-bearing projection integrally formed with said clapper arm and aflixed to one side of said rotor shoes, a second hub-bearing element affixed to the opposite side of said rotor shoes, bearings for each of said hubs and means comprising a pair of bearing plates spanning opposite sides. of said core legs, and each provided with a centrally located aperture for housing one of said bearings.

3. In a telephone ringer, a permanent magnet rotor of cast magnet steel, a pair of soft iron shoes welded to said rotor, a stator having a pair of spaced core legs terminating in oppositely disposed :pole-faces and each carrying a ringer coil, a gong, means for supporting said rotor between the pole-faces of said core legs comprising a hubsupporting element ailixed to each of a pair of opposite sides of said rotor shoes, a pair of bearing plates bridging said core legs and each supporting a bearing, which bearings are adapted to receive the hubs carried by said hub-supporting elements, and a clapper sup-port formed integrally with one of said hub-supporting elements and supporting a clapper adapted to strike said gong when said rotor is actuated in response to the energization of said ringer coils.

4. The combination in a combined telephone ringer and substation induction coil, a laminated core structure comprising a closed rectangular portion and a pair of spaced integral projections extending from one leg of said rectangular portion and terminating in oppositely disposed arcuate pole-faces, a ringer coil mounted on each of said spaced projections, a permanent magnet mounted for rotation between said arcuate polefaces, a clapper carried by said armature, a sound emitting device adapted to be struck by said clapper when said rotor is rotated between said pole-faces upon the energization of said ringer coils, and an induction coil having a core spanning the leg of said rectangular core portion from which said pair of spaced integral projections extend and the opposite leg of said rectangular core portion, whereby said ringer coils and said induction coils are positioned conjugate to each other.

5. A combined telephone ringer and telephone substation induction coil comprising a substantially rectangular laminated magnetic structure having a pair of spaced integral extensions projecting outwardly from one side thereof, a pair of ringer coils wound upon said extensions and forming with said extensions an electromagnetic stator, a rotor comprising a permanent magnet oscillatably supported between the extremities of said extensions and adapted to be operated therebetween upon the energization of said ringer coils, a clapper operated by said rotor, a gong housing said magnetic structure and adapted to be struck by said clapper upon the actuation of said rotor, and an induction coil mounted within the area defined by said rectangular magnetic structure and having a core whose longitudinal axis parallels the longitudinal axes of said extensions and is spaced substantially midway therebetween whereby said induction coil is disposed conjugate to said ringer coils to preclude the possibility of interaction between said coils.

6. A telephone ringer comprising a permanent magnet rotor of cast magnet steel, a pair of soft iron pole shoes welded to said rotor, a stator having a pair of spaced core legs terminating in oppositely disposed pole faces and each carrying a ringer coil, a gong, a clapper arm carrying means for striking said gong when said rotor is rotated between said stator pole faces upon energization of said ringer coils, and means for rotatably supporting said rotor between said stator pole faces, comprising spindles fastened to said pole shoes, bearings for said spindles, and means comprising a pair of bearing plates spanning opposite sides of said core legs and each provided with a centrally located aperture for housing one of said bearings.

7. The combination in a telephone ringer comprising a coil bearing stator having a pair of oppositely disposed stationary pole faces and a permanent magnet rotor mounted for oscillation between the pole faces of said stator when the stator coil is energized, of a gong, means for supporting said gong on said stator, a clapper arm fixed at one point to said oscillatable rotor for oscillation therewith and extending in opposite directions from its point of association with said rotor, one of the clapper arm extensions supporting a striker for engaging said gong when said rotor is actuated, and means for limiting the stroke of said clapper arm comprising a cam adjustably mounted in substantial alignment with the other of the clapper arm extensions.

EMIL DICKTEN, JR. HENRY C. HARRISON. 

